1. Field of the Invention
This invention relates to apparatus and methods which employ belts constructed and arranged to transport bottles, particularly polyethylene terephthalate ("P.E.T.") bottles, along a conveyor line.
2. Description of the Related Art
Apparatus and methods are known to transport objects between work stations. Certain apparatus are provided with conveyor belts and chains to move a variety of different objects.
For example, U.S. Pat. No. 3,124,231 to Ott, Jr. discloses a mechanism to transfer articles vertically, in particular fragile articles such as bulbs or lamps. The mechanism includes a pair of spaced endless belts provided with flexible resilient protuberances, such as parallel ribs or cleats of rubber, which grip the article at its maximum diameter.
U.S. Pat. No. 3,840,111 to Randrup discloses a chain conveyor to engage directly cartons or other containers. The conveyor includes a deflector assembly which is employed to twist the chain about its longitudinal axis for as much as ninety degrees (90.degree.). The deflector assembly consists of deflector sheaves between which an intermediate sheave is disposed. Each one of the sheaves has a chain-receiving groove at it's periphery.
U.S. Pat. No. 3,978,971 to Conrow., et al. discloses a bulb accumulator consisting of a pair of parallel round belts which suspend the bulbous portion of each bulb so that the cullets portion is pendent. The belts may be a polyurethane material. The bulbs are transported to another pair of opposing cleated belts which grip the bulbs from opposing sides and move them forward continuously. A drag strip beneath the parallel round belts contacts the cullets of the bulbs to incline the bulbs away from the direction of travel which causes the bulbs to stack or accumulate so that each bulb is substantially supported by the proceeding bulb.
U.S. Pat. No. 4,422,541 to Lisec discloses an apparatus for conveying insulted glass panes and which consists of a pair of L-shaped supports which extend inwardly under the individual panes. The supports are provided with pressure contact jaws to contact an outside surface of the panes for a reliable conveyance and are moved by a pair of conveyor chains along an underlying guide rail for each support.
U.S. Pat. No. 4,479,574 to Julius, et al. discloses a container transport apparatus for plastic bottles and which consists of a plurality of rigid, elongated container guide members which surround the containers and guide them as they pass through the transport apparatus. A pair of conveyor belts moves the bottles along the guide members. A guide support for the guide members and the conveyor belt is provided with a cutout portion to permit passage of the return portion of the belts. The guide member is a generally flat rectangular structure with a sloping end portion having a circular aperture cut away to permit a portion of the belt to project outside the sloping end portion and contact the side wall of the bottle.
U.S. Pat. No. 4,802,571 to Born, et al. discloses an apparatus for conveying suspended bottles and which consists of two conveyor belts moved next to one another in a single guide bar which is mounted in the conveyor housing. A conveyor belt is provided upon which the neck bead of the bottle is loosely supported, with play, to be conveyed. An adjustable rail with an adjustable guide strip is provided to vertically position the bottles when conveyed and to accommodate the lateral dimensions of the bottles.
U.S. Pat. No. 4,807,421 to Araki, et al. discloses equipment for handling containers and which consists of a flexible holding member centrally formed with a hole divided into tongues which extend radially inward acting to hold the container in place in the center of the holder.
U.S. Pat. No. 4,823,940 to Cretser discloses a conveyor for flat articles, such as printed circuit boards, and which includes an endless conveyor belt disposed on its edge to pass around a pulley provided with a lower, laterally outwardly projecting flange forming a lower guide surface for the lower edge of the associated pulley. An upstanding generally U-shaped guide for the belt forms an elongated groove extending between end pulleys.
U.S. Pat. No. 4,927,004 to Leaton discloses an apparatus for feeding and discharging discrete objects such as gem stones and which includes two conventional toothed belts which pass around top pulleys and bottom pulleys. Each belt carries a series of equispaced containers formed of a flexible material such as polyurethane rubber.
U.S. Pat. No. 5,145,055 to Kondo discloses a conveyor device for printed circuit boards and which includes a pair of spaced apart endless roller chains each of which is guided by a guide rail. A plurality of support members fixed to the chains to move therewith have a clamp plate member rockably mounted on each of the support members to move between opened and closed positions and cooperate with the corresponding support member to clamp the side edge portion of the circuit board therebetween when the clamp plate member is in the closed position.
Among these inventions, however, none provide for variable gripping of the bottle neck ring to ensure controlled, efficient movement of each bottle along the conveyor line. Although the Julius and Born, et al. patents disclose belts which contact the walls of the bottle and upon which the bottle neck rings are loosely supported with play, respectively, these conveyor belts are less efficient and determinative of the positive gripping pressure employed to transport the bottles than the present invention. This is an important concern in those situations where the conveyor apparatus is elevated off the assembly line floor. It is important to have the bottles securely gripped so that there is virtually no possibility of these objects jamming or falling onto the production floor and personnel below.
In addition, none of the these patents disclose a simplified apparatus with conveyor belts to be constructed with a groove defined by resilient material to engage and release the bottles as does the present invention. The conventional systems, such as Born, et al., restructure the guide slot at the inlet and outlet regions of the apparatus to receive and discharge the bottles. This is a more complicated structure than that of the present invention, and requires more space and is more expensive.
The cross section of the conveyor belts of the present invention is adapted to retain the belts in their support blocks regardless of the speed at which they are driven during conveyor operations.